A phrase originating from the San Francisco Bay Area, used when someone does something very risky, regardless of the consequences. Made popular with the League of Legends community by pro gamers TSM.Reginald and Dan Dinh.

A - "Dude you gotta try this cliff jump, it's so worth it"
B - "But it would be my first time and I'm nervous"
A - "Baylife it bro"
B - "((Stops for a moment to decide, maybe take a quick breather))...Baylife!!!!*Jumps*
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A - "You need to quit being nervous around girls man, you need to get laid!"
B - "But that's just me man, I really want to, but it's hard"
A - "Baylife it, who cares what they think about the real you"